The overall aim of this effort is to develop a fully functional voice- activated computer system for clinical trials of hypertension to optimize data collection and reporting. This system will 1) facilitate data collection; 2) improve accuracy; 3) improve reliability and completeness; 4) improve timeliness. A randomized controlled study is proposed to demonstrate that this is an easier to use, more efficient, cost effective, complete and accurate method for clinical trials of hypertension than current systems. The specific aims for Phase Il are: 1. Software engineering: refinement and expansion of actual system a. Inward database connections with coding databases (ICD-9, WHO-ART, COSTART). b. Outward database connections, allowing electronic transfer of data. c. Implementation of an audit trail d. Generalization of the knowledge base e. Refinement of the user interface 2. Testing and evaluation -- test site specific activities a. Collection of ergonomic information and user feedback for multiple test sites b. Beta testing at multiple sites c. Evaluation of the system in a randomized controlled study 3. Transition to commercial development a. Market survey of hypertension clinical trial sites b. Development of a business and marketing plan for the commercialization phase